Feed chute for stokers and the like



y 7, 1931- A.;J STOCK. JR 1,813,590

FEED CHUTE FOR STOKE-RS AND THE LIKE Filed Feb. 23, 1926 [NVEN TOR.

A TTORNEY Patented July 7, 1931 PATENT oF-F ca ARTHUR J. STOCK, JR, or LAKEWOOD} OHIO FEED Cl-IUTE FOR STOKERS AND THE LIKE Application filed February 23, 1926. Serial No. 89,880.

i This invention relates to feeding devices,

and more particularly to chute construction. It has been usual heretofore in stoker equipment for instance to bring a chute down at an incline from a bin above to the hopper of the stoker, such chute having its lower side or floor widening out fan-shape and lying in a uniform plane. If coal containing mixed sizes is passed down through such device,

W w the small particles tend to run to the middle,

and the larger pieces tend to segregate to the sides, thus interfering with a uniform feed across the grate.- It has accordingly given considerable trouble in the economical operation and maintenance offstokers and furnaces; In accordance with the present invention, however non-uniform coal can be used without difliculty. To the accomplishment of the foregoing and related ends, the

* invention, then, consists of the means hereinafter fully described and particularly point ed out in the claims, the annexed drawings and the following description setting forth in detail certain features embodying the invention, such disclosed means constituting however, but one of the various forms in which the principle of the invention may be applied. j

In said annexed drawings; a

:Fig. 1 is a front elevational view showing a; construction embodying my invention Fig. 2is a side elevation; Fig-3 is adetail of a modification, and Figs. 4 and 5-are sectional details illustrating the relations in a general ly conical segment form, 1

Thestokermaybe of-any usual or .preferred type, and showing of detail further than the hopper S is accordingly unnecessarys Extending between the bunker or bin outlet B and the stoker hopper S, is a chute C'which expands out or diverges laterally in approaching the stoker. As shown in the form illustrated in Fig. 1, the posterior wall orfloor l of the chute is arched up centrally or more or less completely coned. At the o desirable to counter-act the tendency for unlower end is a verticallimiting Wall 2 and spaced therefrom is another limiting wall 3, whilealong the chute a top wall f may be provided, spaced ordinarily at a uniform distance from the bottom wall 1. In some cases, 5 I may corrugate the bottom wall, the corrugations expanding or widening from the up per to the lower end of the chute, or instead of full corrugations there may be two or more intersecting planes 5, in its most elaborate 5 form all together approximating a general conical shape (see Fig. 3).

Mathematically viewed, the invention includes those surfaces which so change the direction and magnitude of the force orforces causing the flow of the entire body of material, generally theforce of gravity, that the resultant of the forces causing-anyparticle to flow lies substantially in a plane which passes through a normal from the particle to the surface and'that straight line lying in or tangent to the surface at the foot of such normal, which makes the least angle with the force causing the flow of theentire body of material. Thus, substantially, the r'es'ult- (0 ant force acting in any particle is independent of the size or relative gravitational mass of that particle or of the particles to either side of it. 1 r i In use, when fuel of nonuniform or un- 7 graded character-is passed down from the bunker or outlet of restricted cross-sectional area, it spreads evenly on the floorl, the angle of slope along'any path and the frictional drag beingsuch as to promote the same effect on all particles, thus preventing tendency to segregate the larger from the smaller particles. Other materials-beside fuelcan be handled in devices of such contour, the advantages applying in any case where it is i graded materials to segregate.

It is furtherpointed out that the Velocity of the fuel as it starts todnove along the conical distributing surface is very slow, due

a different path, is substantially zero.

to the fact that in the feeding of fuel or material to which the present invention particularly appertains, is maintained in the stoker hopper, and in my improved distribut ing device in a flooded condition, and also that this velocity is cont-rolled by the rate at which the stoker removes fuel from the stoker hopper S. Hence, the direction taken by any particle in normal operation is substantially only dependent upon the slope of the surface over which it slides, since the kinetic energy of that particle, which might cause it to take In actual operation the velocity of the fuel as it enters the distributing device is momentarily interrupted, and'subsequently in its passage through such device incident to the improved structure thereof the gravitational velocity of the particles of material as they travel downwardly in an increasingly widening stream is held constant along any transverse plane, and hence segregation is prevented. As described hereinbefore the distributing device comprises notonly a lower distributing plate 1 but a confining cover or surface 4, between which two members the material is moved from the hopper B in a progressively widening stream to the stoker receiving area S. The purpose of this plate or surface t is to confine the material in' its passage over the plate 1 and to thereby prevent any free run-off of the material in the normal operation of the distributing device.

Other modes of applying the principle of my invention may be employed instead of the one explained, change being made as regards the mechanism herein disclosed, provided the means stated by any of the following claims or the equivalent of suchstated means be employed.

1 therefore particularly point out and distinctly claim as my invention 1. A non-segregating feed device provid ing a downwardly sloping flow surface in substantially the form -of a mathematical surface of revolution, said surfacebroadening divergently and havinga lower discharge edge forming a substantially transversely straight line drop-off, and a confining surface adapted to restrict the flow of material. 2. A non-segregating feed device providing a downwardly sloping flow surface in substantially the form of a 'mathematical surface of revolution, said surfaces broadening divergently and having a lower discharge edge forming a substantially transversely straight line drop-0E, and confining surfaces spaced relatively to said sloping and drop-off surfaces adapted to impede the flow of material therebetween.

3. A non-segregating feed device providing a downwardly sloping flow surface broadening divergently and out of a uniform plane and having a lower discharge edge forming a substantially straight line dropoff, a substantially vertical downwardly extending wall integral with said edge, and confining surfaces spaced relatively to said sloping and vertical surfaces and side walls connected to the side extremities of the flow surface and said confining surfaces.

4. A non-segregating feed device providing a downwardly sloping flow surface in substantially the form of a mathematical surface of revolution, said surface broadening divergently, and a, confining surface of complimental form spaced from said flow surface to provide a uniform depth therebetween on any transverse line.

5. The combination with a fuel supply opening of restricted cross sectional area, and a stoker located therebetween having a transversely wider receiving area, of means foi gravitationally transferring ungraded fuel 7 from said supply opening to said stoker and providing a surface broadening divergently and out of a uniform plane and discharging substantially in a straight line transversely of said stolrer, said means being adapted to distribute said fuel laterally over said surface without segregation thereof, and a cover over said first surface and in spaced relation thereto and adapted to control the uniformity-of flow of fuel between said surfaces.

6. The method of gravitationally feeding Ungraded material which comprises flowing the material non-segregatively in a downwardly divergent centrally arched layer, and controlling the flow of said material to prevent free run off. I i

7. The method of feeding ungraded material containing particles' of different size which comprises flowing the material nonsegregatively in a downwardly divergent centrally arched layer, controlling the flow of said material to prevent free run-off, and abruptly restricting the stream to a discharge ina substantially vertical plane. 7 p

8. The method of gravitationally feeding material, which comprises flowing the mate-- rialnon-segregatively in a downwardly divergent cone-like layer and controlling the flow of said material to prevent free run-off.

9. The method of gravitationallyfeeding ungraded fuel to furnace stokers from a hopper supply which comprises transferring the fuel from the hopper discharge to the stoker receiving area in a progressively widening layer inclined to the horizontal and arched centrally, maintaining such fuel in" non-segregative condition, and controlling the flow'thereof between said hopper and stolrer to prevent free run-oif.

'10. The method of gravitationally feeding ungraded fuel to furnace stokers from a hopper having a discharge outlet of considerably less transverse dimension than the stoker receiving area, which comprises transferring the fuel from such hopper to the stol'ierin a progressively widening layer at an angle to the horizontal and centrally'arched, maintaining such fuel in non-se egative condi-' tion, and controlling the 0W thereof between said hopper and stoker to prevent free run-off.

11. The method of preventing segregation in material feeding devices for ungraded material wherein the material is fed in a progressively widening stream, comprising substantially destroying the normal gravitationa1 velocity of said material at the start of such stream, and subsequently passing it over an inclined surface of revolution.

Signed by me this 20th day of February,

ARTHUR J. STOCK, JR. 

